PEBBLE BEACH, CALIF. -- What Graeme McDowell accomplished to sit atop the leader board at the U.S. Open cannot be ignored, because a round of 3-under-par 68 on fair-but-treacherous Pebble Beach Golf Links deserves acknowledgment. Ernie Els, himself a two-time Open champion, matched that score in Friday's second round, and he, too, should be congratulated and anticipated, because as he said, "I feel my game's there."

Ryo Ishikawa's game is there, too, which is somewhat amazing considering he is 18, and his rounds of 70 and 71 leave him at 1 under, tied with Els and Dustin Johnson, the monster hitter who loves this course and has won twice here. All of them are two behind McDowell, the Irishman who said, quite candidly, "I'd be lying if I hadn't thought about picking up the trophy on Sunday afternoon."

But the U.S. Open will have a pulse this weekend not because of any of those developments. McDowell, Els, Ishikawa and Johnson all did their damage Friday morning, and that left the afternoon stage to one of the few characters in golf who can move the needle. Phil Mickelson admitted to being "frustrated" after an opening round in which he managed not a single birdie. Friday, he stormed back into the tournament -- indeed, becoming its dominant figure -- by birdieing six of his first 11 holes. Thus, in a matter of hours, a hum-drum Open turned into a potential sizzler, because Mickelson carded a best-in-the-tournament 66 that left him tied with the group just two back of McDowell.

"Certainly my mood is better," Mickelson said. "I'm a lot cheerier. I feel much better about my position in the tournament headed into the weekend."

No kidding. When the day started, Mickelson said he felt like he needed "something in the 60s." But to do that, he would have to putt far better than he did Thursday, when he missed five birdie putts inside 10 feet. He spent some time Thursday night on the phone with his putting guru, Dave Stockton Sr., adjusting how he addressed the ball. On just the second hole Friday, he stood over a three-footer. No big deal? Think again. He missed one Thursday. If that had continued, early in his second round, he may have ceded the stage to the gaggle that joins him on the leader board.

"Even though it was only a three-footer," Mickelson said, "it was uphill, I was able to be aggressive, roll it in, see a birdie put go in, and it just gave me some confidence."

So here came the charge: birdie, birdie, birdie, par, birdie, par, birdie, the last an aggressive play with a wedge into the difficult, seaside eighth hole. The subsequent 15-footer had to make the rest of the field notice him. His only bogey came at the ninth -- when he was, for one of the few times, above the hole, and missed from four feet -- but he bounced back with a birdie at 11, then finished with seven tidy pars.

Star power, welcome to the leader board.

"It was as easy a 66 as you'll ever see," said Padraig Harrington, who played the first two rounds with Mickelson and carded his second straight 73.

"Easy" is what it's supposed to be for Els. He won the first of his Opens, in 1994 at Oakmont, when he was 24, and his deceptively casual swing and placid demeanor -- not to mention his boundless talent -- seemed to portend big things ahead. He won his second Open in 1997 at Congressional and added a British Open for his third major championship. Move Mickelson and his four majors aside, and Els is easily the most accomplished player in the top 25 at this Open.

But does the fact that he has won on such a stage before mean anything here?

"Sure it will help," Els said. "It's been so long. I've been in all kinds of situations. But there are a lot of guys hungry for a win."

McDowell is among them, and it would be unfair to say he hasn't been better than the entire field thus far. He won his last start, the Celtic Manor Wales Open on the European Tour, and at 30, he feels as if his time in such marquee events is now. He started Friday with bogeys on two of his first three holes -- perhaps the 4:20 a.m. wakeup call had something to do with it -- but then played splendidly, with six birdies, before a three-putt bogey on his final hole.

"I'm not seeing the battle with the rest of the field," McDowell said. "I'm seeing the battle with myself and the golf course. . . . I feel like all facets of my game are in good shape. I'm probably as ready to go into the weekend of a major as I've ever been."

That is how Mickelson, winner of four majors, feels as well. His wife, Amy -- battling breast cancer for more than a year -- and the couple's three children were due to arrive on the Monterey Peninsula on Friday night. Saturday morning, the family will likely rise, go out for breakfast, and then perhaps wile away the hours with some chess, scheduled around Mickelson's practice session.

They would not, he said, think ahead to what another 66 on Saturday might mean, about how close that could bring the trophy. "That's not even in the mind-set," he said. If nothing else, five runner-up finishes -- Mickelson's total in the Open, more than anyone in history -- seem to have taught him to savor what he just did, and relish, not fear, what might be to come.

"I mean, I can't wait for tomorrow's round," Mickelson said. "I love just being on the golf course playing. I don't want the tournament to end. I want to keep playing."